Idling rich
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Joined: Feb 2004
Posts: 53
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From: FH AZ
Idling rich
I have a 93 Vette that I am having an odd issue with. The car runs and drives awesome but idles super rich. If you let it idle more than about 3 minutes it will miss and sputter when you go to drive away. Might be in my head but it seems worse in the summer? Last week I backed it out of the garage to run some errands and ran back inside to grab my wallet. I ended up getting 2 phone calls and the car ended up idling for 20 minutes. When I came back out it was barely running and almost wouldn’t drive at all. It was so bad it fouled the plugs and I had to replace them.
In chasing this down I have replaced the IAC valve, temp sensor, ICM and swapped in heated o2 sensors. No difference. Is this possibly in the tune or do you have other ideas? I’m out.
The car has longtubes, hot cam, and tune from PCM of NC..
In chasing this down I have replaced the IAC valve, temp sensor, ICM and swapped in heated o2 sensors. No difference. Is this possibly in the tune or do you have other ideas? I’m out.
The car has longtubes, hot cam, and tune from PCM of NC..
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Rich
When you put it away, let it idle for about 30 seconds, Shut it off.
then the next day, go out and remove your spark plugs and smell them.
the ones that have leaking injectors will have sooty plugs and Smell like gas.
chances are you need your injectors cleaned.
then the next day, go out and remove your spark plugs and smell them.
the ones that have leaking injectors will have sooty plugs and Smell like gas.
chances are you need your injectors cleaned.
Last edited by coupeguy2001; Aug 18, 2020 at 04:09 PM.
Thread Starter
Advanced
Joined: Feb 2004
Posts: 53
Likes: 7
From: FH AZ
I was wondering about injectors since mine are the 27 year old factory ones. Only thing is all 8 plugs looked like crap when I had them replaced. Could all 8 injectors be equally bad at the same time?
Le Mans Master
Joined: Sep 2013
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From: near the thumb in the mitten
Codes? Fuel pressure regulator diaphragm leaking fuel - check vacuum hose port. Vacuum leaks. MAP sensor, coolant sensor skewed, what does DIC read. DIC uses Engine Fuel Management coolant sensor. Gauge uses different sensor. Super rich will kill cat converters if still equipped.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Injectors
If your fuel has ethanol in it, and your injectors are greenish and silver, they can be affected by today’s fuels.
and that would be ALL of them.
i played around with an intake, a fuel rail, fuel pump, a bucket of mineral spirits, an injector connector and a 9 volt battery.
i can tell with that setup on the bench if the injectors are leaking.
the mineral spirits are less volatile than gas and does not stink as bad.
at 45 lbs, if they are going to leak, they will.
openin and closing them multiple times, then leaving them pressurized, i put white pieces of paper under each injector.
after that, it’s easy to see which ones are leaking.
and that would be ALL of them.
i played around with an intake, a fuel rail, fuel pump, a bucket of mineral spirits, an injector connector and a 9 volt battery.
i can tell with that setup on the bench if the injectors are leaking.
the mineral spirits are less volatile than gas and does not stink as bad.
at 45 lbs, if they are going to leak, they will.
openin and closing them multiple times, then leaving them pressurized, i put white pieces of paper under each injector.
after that, it’s easy to see which ones are leaking.
Last edited by coupeguy2001; Aug 18, 2020 at 08:16 PM.
